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Item type:Publication, Access status: with files , Extraction of oil, carotenes and tocochromanols from oil palm (Elaeis guineensis) fruit with subcritical propane(2023-03-24); This work aims to screen the extraction of oil and bioactive compounds including carotenes and tocochromanols from oil palm fruit with subcritical propane and without using a cosolvent. The overall extraction curves of palm oil with subcritical propane were studied and compared to those extracted with supercritical carbon dioxide. Carotenes and tocochromanols were evaluated not only in the extracted oil. but also in the oil of residual fiber in order to calculate the efficiency to recover these valuable compounds. The experimental results showed that oil yield of up to 70 % could be obtained within 120 minutes with subcritical propane at 50 bar and a flow rate of 35 kg·h-1·kg-1-. It was also shown that compressed propane is an excellent solvent for the extraction of oil enriched in carotenes and tocochromanols. Subcritical propane extraction can be used as an alternative process for the simultaneous recovery of these valuable minor components from palm fruit.Publicationtype: Journal ArticleScopus© Citations 2 59 63 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Extraction of oil and minor compounds from oil palm fruit with supercritical carbon dioxideA significant quantity of tocochromanols and carotenoids remains in the residual from palm oil production by traditional screw pressing. Supercritical carbon dioxide extraction was used as alternative method with the purpose to recover better these valuable minor compounds. Total oil yield and co-extracted water were investigated in the course of extraction. Tocochromanols and carotenoids were evaluated, not only in the extraction oil, but also in the oil of residual fibre. Modelling of extraction process was also performed for a further up-scaling. The results showed that oil yield up to 90% could be observed within 120 min. Supercritical carbon dioxide (SCCO2) could extract tocochromanols and carotenoids with concentration in the same range of normal commercial processing palm oil, while co-extracted water remained rather low at a level of 2–4%. Moreover, recovery efficiencies of these minor compounds were much higher in case of extraction processed with supercritical carbon dioxide than those with screw pressing method.Publicationtype: Journal ArticleScopus© Citations 14 295 343 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , 209 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Supercritical fluid chromatographic separation on preparative scale and in continuous mode(2018-04-01); Chromatography with supercritical fluids (SFC) is a powerful tool for carrying out separations of substances with very similar structure and volatility, such as isomers of various kinds. In this contribution, we discuss the separation process aiming at the recovery of products on a much larger scale than analytical. Nevertheless, for developing such a process, the separation is carried out first on analytical scale to determine optimum operating conditions and select stationary phase, mobile phase, and co-solvent (modifier), if necessary. Determination of isotherms is helpful for simulating the separation process. Verification of the separation process includes the recycling of the mobile phase. The chromatographic process can be a batch process in the elution mode, or a continuous process, approximated as simulated moving bed (SMB). The batch SFC process, although using a higher quantity of mobile phase is less cost intensive than the SFC-SMB process.Publicationtype: Journal Article198 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Calculation of phase equilibria and their relation to separation with supercritical fluids(2018-04)Supercritical fluids are a unique class of solvents because solvent power is adaptable by changing pressure and temperature, or density. To make use of this feature, P,v,T- and phase equilibrium-behavior must be known. The best way is by calculation. Tools are available, most of them derived from cubic equations of state. These tools are applicable to fluid mixtures with components of very different volatility, such as supercritical fluids and low volatile compounds. Multi-component mixtures are modeled by combination of binary systems. In processes, process fluids occur at very different conditions. Cubic equations of state are successfully used to calculate P,v,T-behavior and composition of the process fluids for all different conditions. Furthermore, thermodynamic functions, such as enthalpy and entropy, are an intrinsic result of phase equilibrium modeling. A useful calculation package can be freely downloaded from: PE 2000 http://www.tuhh.de/v8/links-downloads/pe-2000/download.html.Publicationtype: Journal Article158 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Supercritical process technology related to energy and future directions - An introductionProcess technology comprises the application of fundamentals to processes, as for example phase equilibria and reaction kinetics, the verification of process steps, as for example in specific reactors, and the design of process sequences to produce a product (energy) from raw materials. For the special field of supercritical fluids related to energy processes it includes single process steps as well as process step sequences and whole processes. Also, process technology is not restricted to any specific application. It includes processing of renewable (bio-based) materials, fossil materials, and processes to access these materials. In general, process technology related to the application of supercritical fluids is based on the exploitation of the specific properties of supercritical fluids. This includes the varying properties of supercritical fluids and the interactions of supercritical fluids with the processes materials, such as a drastically reduced viscosity. Supercritical fluids guarantee an enclosed processing with emanations that can be adjusted. Supercritical fluids have been used in quite a number of processes and process steps related to production of energy, mostly in laboratory and demonstration scale. Among these processes are: the ROSE process, coal liquefaction and gasification, the production of oil from oil shales, and of oil from oil sands. Supercritical fluids have been proposed (and partially are used) for: enhanced oil recovery, emulsion splitting (oil-water), enhanced gas recovery, bitumen separation, recovery of hydrocarbons from particles (remediation of soil), de-asphalting, removal of fine particles, and others. Supercritical fluids are proposed for deep drilling (spallation drilling), and for the production of energy from hydrothermal flames. Process technology using supercritical fluids has to provide the equipment for the processes. Keys to future success will be: simple design, simple operation, high efficiency (higher than burning the feed), and a thorough training of the community in the specific abilities of supercritical fluids.Publicationtype: Journal Article212 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Mono- and di-acylglycerol synthesis in CO2-expanded acetoneEnzymatic esterification of glycerol and palmitic acid was performed in acetone expanded by CO2 at 40-60 °C and 65-85 bar. Novozyme 435, Lipozyme RM IM, Lipozyme TL IM and Lipomod 34P were screened to select a suitable enzyme for the study. The effects of additional water and molar ratio of glycerol to palmitic acid on the selectivity to mono- and di-acylglycerol were investigated. Response surface method was used to describe the dependency of pressure, temperature, and enzyme concentration on the conversion of palmitic acid. Optimum condition was finally selected at 85 bar, 50 °C and 25% of Novozyme 435 related to the amount of dissolved fatty acid.Publicationtype: Journal Article22 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Comparison of different pretreatment methods for lignocellulosic materials. Part I: Conversion of rye straw to valuable productsThe conversion of lignocellulose to valuable products requires I: a fractionation of the major components hemicellulose, cellulose, and lignin, II: an efficient method to process these components to higher valued products. The present work compares liquid hot water (LHW) pretreatment to the soda pulping process and to the ethanol organosolv pretreatment using rye straw as a single lignocellulosic material. The organosolv pretreated rye straw was shown to require the lowest enzyme loading in order to achieve a complete saccharification of cellulose to glucose. At biomass loadings of up to 15% (w/w) cellulose conversion of LHW and organosolv pretreated lignocellulose was found to be almost equal. The soda pulping process shows lower carbohydrate and lignin recoveries compared to the other two processes. In combination with a detailed analysis of the different lignins obtained from the three pretreatment methods, this work gives an overview of the potential products from different pretreatment processes.Publicationtype: Journal ArticleScopus© Citations 57 29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Biocatalytic separation of (R, S)-1-phenylethanol enantiomers and fractionation of reaction products with supercritical carbon dioxide(Elsevier, 2011)10 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Comparison of different pretreatment methods for lignocellulosic materials. Part II: Influence of pretreatment on the properties of rye straw ligninSeveral processes have been suggested to convert various types of lignocellulosic biomass into lignin products and saccharides. This paper evaluates the suitability of an organosolv process, a process using soda, a hydrothermal process and a process developed in this work, called the " Aquasolve process" for inclusion into a lignocellulosic biorefinery concept. Part II of this paper investigates the influence of the different pretreatment processes on the properties of rye straw lignin and evaluates their ability to produce high recoveries of high quality lignin. Specifications for high quality lignin products are defined and the isolated lignin fractions are analysed by Klason lignin, carbohydrate and ash content, elemental analysis, thermo-gravimetric analysis, 31P NMR, and size exclusion chromatography. The organosolv process shows the largest lignin recovery, followed by the soda and Aquasolve processes. Lignin products from the soda process, the Aquasolve process and with reservation the organosolv process show interesting properties for polymer applications.Publicationtype: Journal ArticleScopus© Citations 148 33